The present invention refers to a chain connecting element.
Chain connecting members find especially application in high-performance round link steel chains as utilized in underground mining. It is known that when using chain connecting links in the Kenter-mode of construction, after use, the disassembly can prove difficult, since the long clamping pin can seize due to rust in the obliquely extending bore which extends through the opposing limbs of the two link halves and the crosspiece. In addition, the clamping pin as well as the crosspiece disposed between the two link halves are exposed to shearing stress as a result of stress to which the two link halves of the chain connecting link are subjected, so that the extraction of the clamping pin from the long bore is further complicated. Furthermore, the extraction of the clamping pin requires a long spike which, during extraction process, is subjected to intense bending stress which it can resist to an only a limited extent.
The Kenter lock known from DE-PS 201 224 has been refined in most varying embodiments. The refinement according to DE 90 10 317 U proposes a chain connecting link especially for high-performance-round steel chains which use a locking ball as locking element which can be fixed in position by a clamping pin lodged obliquely relative to the chain link plane. A relatively short clamping pin can be used which, should it seize due to rust within the bore of the crosspiece, can be easily extracted from the crosspiece to the other side with a short, respectively rigid spike. This simplifies the assembly as well as the disassembly. A disadvantage is however the increased production costs and the fact that the locking ball represents an additional component, thus increasing the number of parts. This disadvantage is also true for the chain connecting link disclosed in DE 196 52 262 C2 which uses, instead of the locking ball, separate locking elements that are connected with each other by a pivot bolt which extends through the crosspiece component. Pivoting by 90° causes locking elements to embrace guide surfaces on the limbs of the link bracket so that the crosspiece component is secured from falling out from the chain connecting link. The fixed positioning of the ring element is realized by a safety pin driven in parallel to the pivot axis.
Furthermore, DE 20 2006 016 032 U1 discloses a chain connecting link in which two link brackets coupled via their limbs are locked by a crosspiece inserted transversely between the limbs of the link brackets. Depending on a dimensioning of the chain, the latter as well as the link brackets can have a weight of several dozens of kilograms of weight so that during both assembly of the chain connecting and disassembly of the chain connecting link, the entire chain extending from both sides of the chain connecting link must be lifted and turned to enable extraction of the crosspiece.